Triage performance of human gene EPB41L3 and HPV 16/18 viral DNA methylation among hrHPV positive women: a cohort study

Abstract

Background: Methylation-based biomarkers show promise in triaging hrHPV positive women, however, more evidence from population-based prospective studies is required to confirm its utility in real-world settings. Methods: 2000 women from Xinjiang, China were screened for cervical cancer in 2018 and annually followed-up until 2020. Swab samples of baseline hrHPV positive women were used to perform a methylation test targeting the host gene EPB41L3 and HPV16/18 DNA L1/L2 regions. Triage accuracy and predictive values of the methylation test were evaluated in comparison with HPV16/18 and cytology triage using cross-sectional and 24-months outcomes. Results: Overall methylation positivity was 12.4% among hrHPV positive women, and test positivity increased by the histology lesions (7.7% in normal, 9.1% in CIN1, 62.5% in CIN2, 75.0% in CIN3 and 100% in cancer cases, ptrend<0.05). Women being methylation positive at baseline had a significantly higher risk of hrHPV persistence at 12-month and 24-month follow-up (RR12M=1.9, 95%CI: 1.4-2.5 and RR24M=1.7, 95%CI: 1.1-2.5). The specificity of methylation (92.1%) was substantially higher than either HPV16/18 (78.7%, p<0.001) and cytology (79.2%, p <0.001). For CIN2+, the cross-sectional triage sensitivity of methylation appeared slightly higher than HPV16/18 but less than cytology triage with values of 70.6%, 64.7%, and 94.1% respectively (pexact=1.000, and pexact=0.213 respectively) .The longitudinal sensitivity of methylation over 24-month follow-up was 56.0%, as compared to 64.0% (pexact=0.688) for HPV16/18 and 76.0%, (pexact=0.125) for cytology. Methylation test showed high positive predictive values for CIN2+ (41.4% at baseline and 50.0% at 24-month follow-up), while the CIN2+ risk of methylation negative women (cNPV) remained considerable (2.5% at baseline and 6.9% at 24-month follow-up). Conclusions: Methylation could improve triage specificity and colposcopy efficiency, and predict elevated risk of hrHPV persistence and CIN2+ during 24-month follow-up, suggesting that DNA methylation could be a useful triage tool for hrHPV positive women. Women negative by either methylation, HPV16/18 or cytology would still require careful follow-up.